Exploring ultra-cold phenomena (to 1908)

James Dewar initiated research into electrical resistance at low-temperatures. Zygmunt Florenty Wroblewski conducted research into the electrical properties at low temperatures, though his research ended early due to his accidental death. Around 1864, Karol Olszewski and Wroblewski predicted the electrical phenomena in ultra-cold temperatures of dropping resistance levels. Olszewski and Wroblewski documented evidence of this in the 1880s.

Onnes purchased a Linde machine for his research. On March 21, 1900, Nikola Tesla was granted a US patent for the means for increasing the intensity of electrical oscillations by lowering temperature, which was caused by lowered resistance, a phenomenon previously observed by Olszewski and Wroblewski. Within this patent it describes the increase intensity and duration of electric oscillations of a low temperatureresonating circuit. It is believed that Tesla had intended that Linde's machine would be used to attain the cooling agents.

Sudden and fundamental disappearance

Heike Kamerlingh Onnes and Jacob Clay reinvestigated Dewars's earlier experiments on the reduction of resistance at low temperatures. Onnes, with assistants at his facility, began the investigations with platinum and gold, replacing these later with mercury (a more readily refineable material). Onnes research of the resistivity of solid mercury at cryogenic temperatures was accomplished by using the Onnes own process of attaining liquid helium as a refrigerant. At the temperature of 4.19 K, he observed that the resistivity abruptly disappeared (the measuring device Onnes was using did not indicate any resistance). Onnes disclosed, in 1911, his research in a paper titled "On the Sudden Rate at Which the Resistance of Mercury Disappears". Onnes stated in that paper that the "specific resistance" becomes one thousand, thousands of times less in amount relative to the best conductor at ordinary temperature. Onnes later reversed the process and found that at 4.2 K, the resistance returned to the material. The next year, Onnes published more articles about the phenomenon. Initially, Onnes called the phenomenon "supraconductivity" (1913) and, only later, adopted the term "superconductivity". For his research, he was awarded the Nobel Prize in Physics in 1913.

Onnes conducted an experiment, in 1912, on the usability of superconductivity. Onnes introduced electrical oscillations into a conductive ring and removed the battery that generated electrical oscillations. Upon measuring the electrical current, Onnes found that the intensity of electrical oscillations did not diminish. This was experimental proof of Tesla's US685012 patent. The current persisted due to the superconductive state of the conductive medium. In subsequent decades, superconductivity was found in several other materials. In 1913, lead was found to superconduct at 7 K, and in 1941 niobium nitride was found to superconduct at 16 K.